Apparatus for controlling the speed of reproduction of sound machines



Sept. 7, 1943. H. P. CLAUSEN 2,329,106

APPARATUS FOR CONTROLLING THE SPEED OF REPRODUCTION OF SOUND MACHINES Filed Nov. 50, 1940 INVENTOR Henry I? C/ausen AH-s.

, & REPHODUMNG Patented Sept. 7, 1943 UNITED STATES PATENT OFFICE APPARATUS FOR CONTROLLING THE SPEED OF REPRODUCTION CHINES OF SOUND MA- Application November 30, 1940, Serial No. 367,926

11 Claims.

This invention is concerned with improvements for use in combination with sound reproducing machines such as those employed in transcribing recorded dictation, by means of which the speed of reproduction may be varied to suit the transcriber's desires.

A general object of the invention is to provide, in a new structural form and Operating in a novel way, a control system for use in conjunction With dictation transcribing machines by means of which any one of several speeds of reproduction of the recorded matter may be substantially automatically obtained,

A further object of the invention is to provide automatically operating means which acts to back space the transcribing machine at intervals and during retracing of the back spaced portion of the sound record cutting off the sound reproducer so that the transcriber may proceed to transcribe the previously heard subject matter without being distracted.

A still further object of the invention is to provide, in a combination of the above type, an automatically operating adjunct by means of which the back spaced subject matter is audibly reproduced at a different intensity in relation to normal reproduction, to signal the fact that, after the back spaced subject matter has all been reproduced, fresh subject matter is then to be produced.

Other and more detailed objects of the invention will be apparent either by direct reference to or by the following description of the embodiments of the invention disclosed in the drawing for purposes of illustration.

This invention resides substantially in the combination, construction, arrangement, relative location of parts, steps and series of steps, all as will be explained in full detail hereinafter.

In the accompanying drawing, the single figure is a diagrammatic view of an embodiment of this invention.

There are a number of known types of mechanism for directly controlling or eifectively controlling the speed of sound reproduction from dictation transcribing machines in order to adapt them to the convenience or skill of the operator. For one reason or another these various prior art combinations have disadvantages and limitations which tend to characterize them as not the best solution of the problem.

The invention herein disclosed is concerned with the same object but it is believed accomplishes it in a more practical and useful manner without any apparent attendant disadvantages.

The subject matter of this invention is associated entirely with the transcribing machine and is in no way connected with the dictation or sound recording machine, or that portion thereof when embodied as a unit with a transcribing machine as is sometimes done.

It will become clear from the following description that the nature of the subject matter of this invention is such that it may readily be employed with all the known types of dictation transcribing machines, whether they use fiat rigid record tablets, thin flexible record tablets, \vax cylinders, magnetic records, phonographlc records, and the like.

For purposes of illustration, the mechanism herein disclosed has been illustrated in association with a dictation reproducing machine of the type disclosed in the copending application of Barton A. Proctor and Ferdinand C. W. Thiede. Serial No. 218,082, filed July 8, 1938, now Patent No. 2,296,870 issued September 29, 1942. Only so much of that machine has been diagrammatically illustrated herein as is necessary to a full understanding of the present invention. The full details of a machine of this type are disclosed in the above-mentioned application.

This type of dictation reproducing machine as well as recording machine) employs a transparent flexible disc of cellulose acetate which rotates on a support which is transversely curved and may be pictured as similar to a turtles back. In this machine and as illustrated here, there is provided a spindle I having a key record disc receiving support 2 on which the thin flexible record disc 3 is impaled. As will appear as the description proceeds, this mechanism if desired can with little modification be employed with a rigid record disc. The spindle I is journalled in a carriage 4 which is supported for linear movement in a radial direction with respect to the record tablet. The carriage is normally supported on rods (not shown) so that it may slide for example from left to right and right to left.

Mounted on the spindle l is a worm wheel 5 which meshes with a threaded rod 6 connected to the carriage 4 so as to be rotatable with respect thereto. The rod 6 is engaged by a fixed threaded nut I so that as the rod rotates it moves to the left or right, depending upon its direction of rotation. A ratchet wheel or disc 8 is secured to the end of the shaft 6. The mechanism is driven by a pair of friction wheels 9 and ID, the latter of which is positioned so as to engage the lower surface of the record disc 3 and the former as to move wheel 9 into engagement with the disc 3 when the machine is put into operation so as to frictionally grip the disc between it and the wheel I0. Wheel I is driven by a suitable power source such as an electric motor (not shown). The reproducing head II is illustrated as of the piezoelectric crystal type having a stylus which engages the record groove or impression on the disc 3. It is of course apparent that other types of reproducing heads can be used.

When a machine of this type is put into operation, nut I is disengaged from the shaft 6 and with a disc 3 impaled on the spindle I, the carriage 4 is moved to its extreme right position so that the stylus of the reproducing head engages the disc at a point near its center. As th wheels 9 and I6 cause the disc 3 to revolve, the carriage 4 is slowly moved to the left through the coaction of worm wheel 5, threaded rod 6, and fixed nut I. The result is that the record 3 moves in a radial direction at a slow rate of speed as it revolves so that the stylus of the reproducing head travels in the record impression in the disc from its center to its periphery. The record impression is made on a similar machine and consist-s of a plurality of convolutions forming a spiral of very slowly increasing diameter. In a practical form of the machine the separation between adjacent convolutions of the record is about 0.01 of an inch.

Mounted on the lower end of the spindle I is a contact I2 positioned to engage a contact I3 mounted on the carriage 4 and insulated therefrom. The contact I2 engages the contact I3 once for each revolution of the disc 3. The carriage 4 is normally grounded as shown. Contact I3 is connected by wire I4 to an on and off switch I5 which in turn connects to an electromagnet I6 whose circuit is completed to a suitable grounded current source IT.

A normally open switch I8 is controlled by the magnet I6. Switch I8 has one terminal grounded and the other side connected to the movable contact of a single pole double throw switch I9 controlled by an electromagnet 32. Depending upon whether magnet 32 is energized 0r deenergized switch I8 completes the circuit from ground through switch I9 to operate either magnet 26 or magnet 33. The magnet when energized withdraws a pawl 26 from engagement with a ratchet wheel 23 connected to a shaft by means of a spring 24. A switch arm 25 is connected to the ratchet wheel 23, both mechanically and electrically, and operates over a series of contacts 26. Some of the contacts 26 are respectively connected to another series of contacts controlled by a switch blade 21. This switch blade is connected through a single pole double throw push button switch 28, when in the normal position shown, to a grounded electromagnet 29. The electromagnet 29 controls a ratchet 30 which cooperates with the ratchet wheel or disc 8.

The normally open contact of switch 28 is connected to the ungrounded side of the battery source I'I. One terminal of magnet 32 is also connected to the ungrounded side of the current source I1 and its other terminal is connected to the shaft which supports the ratchet wheel 23, by means of wire 3|. The magnet 32 controls the switch I9. It also acts when energized to open a normally closed switch 34 which is in circuit with a sound reproducing device or headphone 35. This headphone is connected to the output terminals of an amplifier 36 which is preferably of the vacuum tube type. The input terminals of the amplifier are connected to the pick-up or sound reproducing head II. Connected so as to form a shunt across the switch 34 is a switch 31 which has the contacts 38 and 39. The blade of switch 31 is connected to one side of switch 34, contact 39 is connected directly to the other side, while contact 39 is connected to the same side through a resistance 40.

The operation of this system is as follows: Assuming for the moment that the transcriber is able to keep up with the rate of reproduction of a particular piece of recorded matter, switch I5 will be open and the reproducing machine will operate normally without the functioning of the invention herein disclosed. Whenever the transscriber wishes to back space the machine, he simply operates switch 28 the necessary number of times to cause a back spacing movement as between the record disc 3 and the stylus of the reproducer of the desired amount. The repeated operation of switch 28 causes impulse energization of electromagnet 29 which operates the pawl 36 to back space the mechanism through the ratchet wheel 8. For purposes of description it may be assumed that for each operation of switch 28 the record disc 3 will be back spaced one sound record groove.

When because of the fact that a particular piece of dictated matter has been recorded at a high rate of speed, or because the transcriber for any reason is not able to keep up with that speed of reproduction, the reproducing and recording machines normally operating at the same constant speed, the mechanism of this invention may be used. In order to use it the operator first closes switch I5. Upon the engagement of contact I2 with contact I3 the first time after switch I5 is closed, the circuit for magnet I6 is completed. This causes switch I8 to close, completing the circuit for magnet 33. Thereupon ratchet 33 moves ratchet wheel 23 one step in a clockwise direction so that the switch blade 25 moves to the first contact of the group 26. The switch arm 25 stays in this position, even though spring 24 has been stressed so as to tend to return it and the ratchet wheel 23 back to initial position, because pawl 26' is holding it. At this point with the construction shown nothing happens, because the contact at that position is not in any circuit.

The next time contacts I2 and I3 close the same operations are repeated so that switch arm 25 moves to the next contact in a clockwise direction. Assuming the transcriber has decided upon a rate of transcription corresponding to a position which the switch blade 21 will take when it is moved in a counter-clockwise direction to engage the first of its contacts, and assuming switch 21 has been so placed, it will be seen that a circuit is now completed from the current source I! through magnet 32, wire 3|, switch blade 25, switch blade 21, switch 28, and to ground through magnet 29.

Energization of magnet 29 operates the shaft 6 through the pawl 30 and ratchet wheel 8 in a. reverse direction to back space the record disc 3 a desired amount. The energization of magnet 32 opens switch 34 and also operates switch I9 to its other contact, connecting switch I8 with magnet 20. Magnet 32 remains energized, holding switch I9 in the position described. The timing of relay I6 is such, however, that by the time switch i 9 has been thus operated switch It will have opened, with the result, however, that the circuit to magnet 20 will not be completed until the next engagement of contacts I! and I3, which will be about the time of one revolution of the disc 3 if it is to be back spaced about one revolution, that is, equal to one record groove convolution. Opening of switch 34 breaks the circuit to the headphone 35 and, therefore, as the record disc moves on again in its forward direction so that the recording head ll re-traverses the back space groove, the transcriber will hear nothing in his headphone.

He has in mind, however, the subject matter recorded on this particular groove and he is able, therefore, to transcribe it, being given an additional period to do so equal to the time it takes the stylus of the recording head to retrace the back spaced groove. Just as the stylus completes this retracing movement, contacts l2 and I3 make, completing the circuit to magnet l6 and closing switch l8 which now completes a circuit through the right hand contact of switch l9 to releasing magnet 20. The energization of magnet 20 withdraws pawl 20' from engagement with the ratchet wheel 23 so that spring 24 can snap the switch arm 25 back to initial position. The ratchet wheel, of course, likewise moves back with the switch arm. I

This movement of switch arm 25 breaks the circuit to magnet 32, so that switch 34 closes and switch l9 returns to its original position. The headphone 35 goes back into circuit just as the stylus reaches the end of the retraced groove so that the transcriber picks up the dictation from there and goes on. The apparatus will repeat these operations so that with the switches 25 and 21 placed as so far described the greatest reduction in reproduction of the dictation will occur, that is, there will be a silent period equal to the length of one record groove for each record groove of sound reproduction. In other words, each period of sound reproduction will be followed by an equal period of silence.

When switch 21 is on the second contact to the right there will be two periods of reproduction for one period of silence; when it is on the third contact there will be four periods of reproduction and one period of silence; and when it is on the last contact to the right there will be five periods of reproduction for one period of silence. Thus it will be seen that the nature of the invention is such that the various rates of sound reproduction can be determined to suit the convenience and skill of the transcriber.

An additional feature of the invention is provided by the use of switch 31 and its associated parts. When the blade of switch 31 is in the position shown during the retracing of the back spaced groove, the headphone will be silent. If the switch blade is on contact 39, even though switch 34 is open, headphone 35 will be in circuit so that during the retracing of the back spaced groove the transcriber will have the dictation recorded in that groove repeated but at a lower' volume because of the fact that resistance I4 is in circuit with the headphone. If the switch blade of switch 31 is on contact 38, even though switch 34 is open, the back spaced groove being retraced will have its record reproduced at full volume so that the transcriber will hear the subject matter therein recorded repeated at full volume.

In the case where resistance 40 is in circuit, as soon as the back spaced groove is retraced tended, therefore,

switch 34 will close, a previously described, and, even though resistance 40 is in circuit, it will be short-circuited through switch 34 andthe volumewill immediately Jump up the retraced groove.

It is of course apparent to those skilled in the art that sound reproducing machines of this type have two well-known forms with respect to the manner in which relative movement between the record tablet and the pick up head is produced. In some machines the pick up head is stationary and the record is caused to move with respect to it as it revolves. In other machines the record tablet is fixed in the sense that while it revolves it does not also have an additional movement but relative movement between it and the reproducing head is eifected by actually causing the reproducing head to move. It will be apparent, of course, that the present invention is equally applicable to either type of machine, and it is inthat all of the claims should apply to the use of the invention with either type of machine, thereby reducing the number of claims necessary 0 adequately protect the invention.

From the above description it will be apparent to those skilled in the art that the principles of construction and operation comprising this invention may be embodied in other physical forms and I do not, therefore, desire to be strictly limited to the description as given for purposes of illustration, but rather to the scope of the claims granted me.

What is claimed is:

1. In a sound reproducing machine of the type described, the combination including a record support, a soundpick-up head, driving means for producin forward relative movement between the record support and head, back spacing means cooperating with said driving means to produce back spacing movement of said head at regular intervals, and selective means controlling said back spacing means for predetermining the relative amount of such back spacing movement, said means for causing relative movement in a forward direction acting continuously to cause relative forward movement and said means for causing back spacing movement including a control device operating in conjunction with said record support.

2. In a sound reproducin machine of .the type described, the combination including a record support, a sound pick-up head positioned to engage a record on said support, means for causing forward relative movement between the record support and the head, means for causing backspacing movement between the record support and head at regular intervals, a sound reproducing device connected to said head, and means controlled conjointly with said means for causing backspacing movement to render the sound reproducing device inoperative during the retracing movement after each backspacing movement.

3. In a sound reproducing machine of the type described, the combination including a record support, a sound pick-up head positioned to engage a record on said support, means for causing forward relative movement between the record support and head, means for causing backspacing relative movement between the record support and head at regular intervals, a sound reproducing device connected to said head, and means controlled conjointly with said means for causing retracing movement to reduce the vol;

indicating the end of ume of sound output from the sound reproducing device during the repetition movement of the record resulting from each retracing.

4. In a sound reproducing machine of the type described, the combination including a record support, a sound pick-up head positioned to engage a record on said support, means for causing forward relative movement between the record support and head, means for causing relative retracing movement between the record support and head at regular intervals, a sound reproducing device connected to said head, and means controlled conjointly with said means for causing retracing movement to render the sound reproducing device inoperative during the sound repetition resulting from each retracing movement and for again rendering the sound reproducing device operative when the. relative position between the record support and head is the same as it was prior to each retracing movement.

5. In a sound reproducing machine of the type described, the combination including a record support, a sound pick-up head positioned to engage a record on said support, means for causing forward relative movement between the record support and head, means for causing backspacing relative movement between the record support and head at regular intervals, a sound reproducing device connected to said head, and

, means controlled conjointly with said means for causing backspacing movement to reduce the volume of sound output from the sound reproducing device during the retracing movement following each backspacing movement and for causing the sound reproducing device to reproduce at normal volume at the end of the retracing movement.

6. In a sound reproducing machine, a support for a record tablet, a sound reproducing head, means for causing relative forward movement between said support and head, so that a record on the support moves at constant speed with respect to said head, and means for periodically causing backspacing movement between the support and head at any one of a number of predetermined selected intervals without interrupting the forward movement of the record whereby the time required to reproduce a given record may be varied.

7. In a sound reproducing machine, a support for a record tablet, a fixed sound reproducing head, means for causing said support to move a record tablet mounted thereon forwardly at constant speed with respect to said head, and means acting periodically upon preselection to cause said support to move to backspace said record with,

support with respect to the spindle and rotational movement of the spindle, a reproducing head with respect to which a record on said spindle moves forwardly at a constant speed, and means acting periodically upon preselection to cause said support to move backwardly a predetermined amount whereby the time required to reproduce a given record may be varied.

9. In a sound reproducing machine, a movable support, a rotatable record receiving spindle mounted on said support, means for simultaneously causing radial forward movement of the support with respect to the spindle and rotational movement of the spindle, a reproducing head with respect to which a record on said spindle moves forwardly at a constant speed, and means controlled by the rotation of said spindle for repeatedly causing reverse movement of said support a preselected amount whereby the time required to reproduce a given record may be varied.

10. In a sound reproducing machine, a movable support, a rotatable record receiving spindle mounted on said support, means for simultaneously causing radial forward movement of the support with respect to the spindle and rotational movement of the spindle, a reproducing head with respect to which a record on said spindle moves forwardly at a constant speed, means for moving said support in the reverse direction, and preselecting means for determining the amount of such reverse movement whereby the time required to reproduce a given record may be varied. 11. In a sound reproducing machine, a movable support, a rotatable record receiving spindle mounted on said support, means for simultaneously causing radial forward movement of the support with respect to the spindle and rotational movement of the spindle, a reproducing head with respect towhich a record on said spindle moves forwardly at a constant speed, means controlled by said spindle for causing interrupted reverse movement of said support at predetermined intervals, and selector means for predetermining said intervals, the reverse movement of the support being accomplishedwithout interrupting the forward rotational movement of said spindle.

- HENRY P. CLAUSEN. 

